Piston shoes,guide means and compact rotor means in radial piston machines



Sept. 23, 1969 K. EICKMANN 3,468,262

PISTON SHOES, GUIDE MEANS AND CO CT ROTOR MEANS IN RADIAL PISTON MAC ES Filed Nov. 5, 1966 4 Sheets-Sheet 1 INVENTOR (04 R1. E/CKMA/WV BY a -pan, @ulwi ATTORNEYS Sept. 23, 1969 K. EICKMANN 3,468,262

PISTON SHO GU MEANS AND COMPACT ROTOR MEAN N R AL PISTON MACHINES Filed Nov. 5, 1966 4 Sheets-Sheet z ATTORNEY 5 Sept. 23, 1969 K. EICKMANN 3,463,252

PISTON SHOES, GUIDE MEANS AND COMPACT ROTOR MEANS IN RADIAL PISTON MACHINES Filed Nov. 5, 1966 4 Sheets-Sheet 3 Fly. .9

d I. I 76 35 2a 34 3a 2:9 -"-/5 l4 i 27 2s 7 7 a a 37 25 24| L X3 X4 INVENTOR KARL E/C/(MAN/V u 9 y. 1 Sm ATTORNEYS Sept. 23, m9 K. EICKMANN 3,4 8,

PISTON SHOES, GUIDE MEANS AND COMPACT ROTOR MEANS IN RADIAL PISTON MACHINES Filed Nov. 5, 1966 4 Sheets-Sheet 4.

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INVENTOR KARL E/C/(MA/VN ATTORNEYS [and 3,468,262 PISTON SI-IGIZ8, GUIDE MEANS AND CGMPACT ROTGR MEAN S DI RADIAL PISTGN MACHINES Karl Eickrnann, 2420 Isshilri, Hayama-machi, Kanagawa-iren, Japan Continuation-in-part of application Ser. No. 389,130, Aug. 12, 1964. This application Nov. 3, I966, Ser. No. 591,796 Claims priority, application Germany, Aug. 14, 1963, R 73,121 Int. Cl. 1804b 1/10 US. Cl. 103-161 Claims ABSTRACT OF THE DISQLOSURE A radial piston machine wherein in a fluid handling body cylinders are arranged in pairs of multiple radial cylinder groups, the cylinder in each pair alternately located radially with respect to each other; pistons oscillating radially in said cylinders; piston shoes associated to said pistons and guided on an axially extended guide surface on the guide ring displaced an axially distance from the piston shoe with an extension guide in another axially extended guide surface on the guide ring displaced an axial distance from and approximately equal to the axial spacing dimension of an adjacent axial group of radially disposed cylinders, the structure resulting in a compound rotor with maximum effective power concentration, and extraordinary large piston stroke, and closely oriented cylinder groups.

RELATED APPLICATION This is a continuation-in-part of my copending and allowed patent application Ser. No. 389,130, filed Aug. 12, 1964, now US. Patent No. 3,304,883, and is related to application Ser. No. 461,483, filed June 4, 1965, now US. Patent No. 3,398,698.

In radial piston machines of the type described in the above copending patent application, the pistons move in their cylinders radially outwards and inwards and thereby take in liquid or gas and expel liquid or gas when the machine operates under power. Some radial piston machines showing pistons with piston shoes, are described in my Patent No. 3,223,046. Radial piston machines with a plurality of cylinder groups are described in my Patent No. 3,270,685. Machines with large piston strokes are described in my Patent No. 3,277,834. Pistons with piston shoes are able to operate relatively effectively with high power. These machines with a plurality of cylinder groups and with rotors which are especially compact make it possible to inexpensively manufacture relatively compact radial piston machines.

It is an object of this invention, to develop a high power, compact and effective radial piston fluid handling machine. The efficiency of the design of this invention is high and the life span of such machines is long. The machine is relatively inexpensive to manufacture.

THE DRAWINGS FIG. 1 is a longitudinal sectional view of a piston shoe made according to this invention.

FIG. 2 is a cross-sectional view through FIG. 1 taken along the line IIII.

FIG. 3 is a view of the piston shoe of FIG. 1 taken from above.

FIG. 4 is a view of the piston shoe of FIG. 1 taken from below.

FIG. 5 is a longitudinal sectional view through FIG. 1 taken along the line V-V.

FIG. 6 is a view of FIG. 2 taken from above.

3,46,252 Patented Sept. 23, 1969 FIG. 7 is a longitudinal sectional view through an example of a rotor of the machine.

FIG. 8 is a cross-sectional view through FIG. 7 taken along the line VIII-VIII.

FIG. 9 is a longitudinal sectional view through a radial piston machine made according to this invention.

FIG. 10 is a cross-sectional view through a part of FIG. 9 taken along the line XAXA and a cross-sectional view of a part of FIG. 9 taken along the line XB--XB.

FIG. 11 is a longitudinal sectional view through another embodiment of a radial piston fluid handling device of this invention.

FIG. 12 is a cross-sectional view through FIG. 11 taken along the line XII-XII.

FIG. 13 is a cross-sectional view through FIG. 11 taken along the line XIII-XIII.

FIG. 14 shows FIGURES 12 and 13 drawn one above the other wherein FIG. 13 is shown by dotted lines, and

FIG. 15 is a cross-sectional view through FIG. 11 along line XVXV.

DESCRIPTION AND EXAMPLES With reference to FIGS. 1-6, piston shoe central part 4 provided on the piston shoe trunnion 2, is directed radially outwards of the trunnion. The outer piston shoe guide flanges 5 are located on the piston shoe central part 4. The axial ends of the piston shoe central parts 4 form the piston shoe guide portions 7. The inner faces of the piston shoe guide portions 7 form the piston shoe guide faces 6. The pison shoe trunnion 2 extends into a normal bore of the cooperating piston.

In accordance with this invention the piston shoes are provided with piston shoe central part axial extensions 8 or with piston shoe central radial extensions 9. The piston shoe radial extension guides 107 can be provided on the piston shoe central part radial extensions 9 and can form the axial end walls of the piston shoe central part extensions 9. The piston shoe central part radial extensions 9 extend into the radial ring grooves 25 or 125 in respective piston shoe guide ring or piston shoe guide casing 19.

The piston shoe guide ring can be rotary or stationary and the piston shoe guide casing 19 can also be either stationary or rotary.

Piston shoe radial extension guide walls 24 can be located on the piston shoe guide rings or piston shoe guide casing 19 and the piston shoe radial extension guides 107 can slide thereon.

The piston shoe central part axial etxensions 8 extend in a direction along the axis away from the piston shoe central part and have the advantage that they have on their axial ends an outer piston shoe guide face and/ or a sideward piston shoe guide face 7 and/or an inner piston shoe guide wall 6. The piston shoe central part extension 8 is so narrowly formed that it is free to enter into a respective rotor radial slot 12 and move in the rotor radial slot 12, i.e., the piston shoe central part extension 8 is smaller than the respective rotor radial slot 12.

An additional piston shoe extension guide 103 is provided on central part axial extension 8. A piston shoe guide 203, which may also have tangential extensions, may be provided between piston shoe central part 4 and its axial extension 8. Because the piston shoe central part extension 8 can be made relatively thin in a radial direction, simple manufacturing of the piston shoe in accordance with this invention is possible. The piston shoe central part extension 8 need only be pressed or cast and thereafter does not need to undergo special machining.

Rotor 15 of the machine shown in FIGS. 7 and 8 is in principle shown in my prior patent application. Two cylinder groups are provided in the rotor, each is spaced from the other in an axial direction. The cylinders of one of the cylinder groups are shown at 16, while the cylinders of the other cylinder group are shown at 17. The rotor has a rotor central bore 13 wherefrom the rotor passages 14 extend into the cylinders 16 or 17. The rotor has also two rotor radial straps 10 on which extended piston guide faces 116 and 117 are provided. These guide faces are suitably extensions of the wall of the cylinders 16 and 17 and serve to guide the pistons inwards and outwards during the long piston stroke. The rotor can also have rotor wall recesse 18. It is of further importance that the rotor is provided with rotor radial slots 12, which are parallel to the axis of the rotor and extend through the cylinders 16 or 17, thereby segmenting the rotor radial straps 10.

The rotor radial slots 12 therefore assure that the piston shoe central part axial extensions 8 can enter into these slots when the machine operates under power and move therein outwards and inwards. The rotor central bore 13 acts for the reception of a control body, explained below. In place of providing a rotor central bore, it is also possible to provide on the rotors, cylindrical, conical, plane or spherical control faces. It is also possible to provide entrance valves or exit valves in place of a control body.

FIGS. 9 and 10 show a rotary radial piston machine in which bearings 33 are provided in the casing 26, bearings which support the shaft 27. The shaft is preferably flexible and connected to the rotor 15.

Control body 28 is located in the casing 26 or its backward cover and is provided with control body passages 23 and control passages 34 and 35. Fluid, such as liquid or gas, flows therethrough into or out of the machine.

During the operation of the machine the rotor passages 14 move over the control passage 34 and and are periodically in communication with the fluid entrance control port or with the fluid exit control ports 34 or 35 during the rotation of the rotor so that the liquid or gas can enter or leave through the control body, its passages and control ports into or out of the cylinders 16 or 17. A roller casing 32 can be further provided in order to bear the rotating support rings 43. The piston shoe guide ring 19 is located on the rotary support rings 43. These parts, together with the rotary casing 32 form the piston stroke control vanes.

The piston stroke or the eccentricity of the guide ring can be changed or turned in the opposite direction through a control device 31. In place of a piston stroke control means or control device 31, it is also possible to set the rotary casing 32 directly into the machine casing so that the piston stroke control means can be eliminated. This machine would then be a radial piston machine with an unchangeable or fixed piston stroke.

It is also possible to eliminate the rotary casing 32 and the rotating support rings 43 with its piston guide rings 19 and to construct the casing 26 directly as a piston shoe guide casing. In such case, it is possible to provide on the casing 26 piston shoe guide flanges 20, 21, 22, 23 or 24 or means to direct piston shoes travel along the control flange of the stationary casing 26.

In the embodiment, the piston shoe guide ring 19 is connected to the support ring 43 and to the rotary casing 32 in a rotatable manner, whereby friction between the piston shoe and the piston shoe guide ring is eliminated or reduced. A plurality of radial ring grooves 25 or 125 are advantageously located in the piston shoe guide ring 19. The rotor radial straps 10 then extend partly into the radial grooves 25 or 125 during the operation of the machine with a large piston stroke. It is thereby possible to enlarge the piston stroke.

While in one of my earlier patent applications special guide rings for the guide of pistons were provided between the pistons of the different cylinder groups and the piston shoes were short in the axial direction so that they could not extend through the neighboring cylinder groups, it is the feature in accordance with this invention that the pis- Cit ton shoe axial extensions 8 extend in an axial direction through the other cylinder groups and are guided behind the other cylinder groups by their piston shoe extension guides 103. The piston shoe central part extensions 8 of the pistons of the cylinders 17 extend through the cylinder group 16 and the piston shoe central part extensions 8 of the piston shoes of the cylinder group 16 extend through the cylinder group 17. The piston shoe central part extensions 8 of the piston shoes of the cylinder group 17 extend further, in accordance with this invention, into the rotor radial slots 12 of the cylinder group 16, while the piston shoe central part extension of the piston shoes of the cylinder group 16 extends into the rotor radial slots 12 of the cylinder group 17 when the machine is operating. The described locations of the piston shoe central part extensions 8 and their extensions into the said rotor radial slots 12 has two advantages. Primarily it makes it possible for the piston shoe central part extensions 8 to enter into the rotor radial slots 12 and it makes it possible that the rotor radial strap segments 10 can extend into the radial ring grooves 25 and of the piston shoe guide ring or piston shoe guide ring casing 19, achieving thereby an extraordinary large piston stroke. It makes it further possible that the two cylinder groups 16 and 17 can be positioned a relatively short axial distance from each other.

These two features make it possible to construct an extremely compact radial piston machine with a plurality of cylinder groups and at the same time to achieve a compact design of such a machine in both the axial and radial direction.

Besides this, the efiiciency is increased because of the larger piston strokes of the machine. Also a longer life span of the machine is assured.

The piston shoes in accordance with this invention can further be provided with piston shoe central part radial extensions 9. The piston shoe central part radial extensions 9 can extend into the radial ring grooves 25 or 125 of the piston shoe guide ring or piston shoe guide casing 19. The piston shoe radial extension guide 107 can be guided in or on the piston shoe radial guide faces 24. If this guide means is provided, then it is possible to eliminate the piston shoe guide faces 7.

If, on the other hand, the piston shoe central part radial extensions 9 are not provided, it is preferred that the piston shoes be constructed with the piston shoe guide faces 7 on the piston shoe guide 3 and further be adapted to guide the piston shoe guide 3 through the inner piston shoe guide faces 6 radially outwards.

The piston shoe end guide faces 7 are guided on the piston shoe guide faces 22 and the outer piston shoe guide faces 5 are guided on the piston shoe guide faces 20 of the piston shoe guide ring or piston shoe guide casing 19.

In the drawings, the piston shoe guide faces 21 constitute the piston shoe guide for the piston shoes of one cylinder group while at the same time they constitute the piston shoe extension guide faces 23 of the piston shoe extension guide 103 of the piston shoes of the other cylinder group.

A piston passage, 39, is shown in each of the pistons 11 in FIGS. 9 and 10, and fluid can flow through the passages 39 out of the cylinder 16 or 17 and thence through the pistons 11 into the inner piston shoe balancing means 38. The fluid flows out of the inner piston shoe balancing means 38 through the piston shoe passages 50, into the piston shoe 1 and branches out of the piston shoe passage 40 into the piston shoe passage branches 41 and 42, which extend into piston shoe balancing means 36 and 37, into which the fluid out of the cylinder 16 or 17 flows. The piston shoe balancing means 36 and 37 are axially spaced from the piston shoe central part radial extension 9 and they are enclosed by the guide faces 20 or by parts of the piston shoe guide rings or piston shoe guide casing 19. The piston shoe balancing means 36 and 37 serve for counteracting and thereby balancing against the fluid pressure which acts out of the interior of the cylinder on the piston 11 in a radial direction. They may serve also as lubrication means for the outer piston shoe guide faces 5 and for the neighboring piston shoe guide faces It should be noted that in rotors 15 of FIGS. 7 and 8 the cylinders 17 of the one cylinder group are displaced between the cylinders 16 of the other cylinder group. In other words, when looking at rotor 15 from an axial direction, the cylinder of the one cylinder group are provided between, and behind or in front of, the cylinders of the other cylinder group. Thus, the piston shoe central part extensions 8 of one cylinder group cannot disturb the radialward movement of pistons and piston shoes of the other cylinder group.

Since this assembly supplies high power from a compact unit, care must be taken that the structure is rigid and strong enough. Therefore, the guide means are provided with radially stabilizing support means 43. These support means extend radially inward of the end of rotor means 15. Thereby the radial strength of the guide means aid in actuating the inward stroke of the pistons against the high pressure of fluid in cylinders 17.

The rotor of the machine must also be strong. In this respect, it is possible to set the rotor passages 14 into the rotor 17, such as, for example, as shown in FIGS. 7 and 8. By so constructing these passages, the radial outwardly directed fluid pressures in the passages 14 oppose about equally the radial inwardly directed fluid pressures thereabout. If rotor hub 13 is so dimensioned that a rigid control pintle 28 of high radial strength and load carrying capability can be received therein, then the rotor 17 can be made partially or totally free from radially directed fluid pressure loading. The rotor 17 then floats upon an oil film around the cylindrical outer face of the control pintle 28. The radial loads are then taken up by the guide means and the reacting loads thereof are borne by the rigid control pintle 28.

It is possible to provide for a radial load carrying capacity in the rotor by utilizing radial bearings at the rotor ends and letting the rotor revolve therein. A floating control body, for example, such as is shown in my US. Patents 3,280,757; 3,062,151 or 3,136,260, can be inserted into the rotor hub 13 and float therein. The radial loads of the fluid in the cylinders are then borne by the guide means and by the rotor. Such rotor means, borne in radial bearings, is not shown in the drawing because those skilled in the art will understand the matter from this description.

It is also possible to obtain high fluid pressures without any leakage by a valve arrangement, such as is shown in my US. Patent 3,249,060, and a sealing arrangement, such as is shown in my US. Patent 3,070,377.

The machine of this invention may be utilized as a multiflow pump, motor or compressor. The respective principles of my US. Patents 3,273,511 or 3,270,685 or the respective components of FIG. 12 could be applied for such purpose.

FIG. 11 illustrates another embodiment of the invention, a multiflow machine. It could also work as single flow pump, motor or compressor, if the plurality of entrance ports and exit ports are combined.

FIG. 11 demonstrates a rigid rotor of high radial load bearing capacity. Rotor 315 is provided with axial extensions 350, constituting shafts 350, or the rotor 315 is borne and fastened on a shaft 350.

Rotor 315 and shafts 350 are borne in radial bearings 352 which are directly or indirectly rotatably borne in the housing or covers 426 or 526 of the machine. The inner bearing shells of bearings 352 are axially located as close as possible to the center of the rotor 315 in order to prevent deflection of the axis of rotor 315 or of the shaft 350.

Each cylinder is provided with a rotor passage 261 or 361 which extends in one axial direction from the respective cylinder through the rotor. Rotor passages 261 extend from cylinder 261 in one axial directiontowards the left in FIG. 11. Rotor passages 361 extend from the cylinders 214 in the other axial directiontowards the right in FIG. 11. The rotor ends are provided with rotary control faces. Control body 253 is located at one rotor end and control body 353 is located at the other rotor end. The stationary and rotary control faces form together the control mirrors 254 at one rotor end and 354 at the other end. Control bodies 253 and 353 are provided with fluid passages and control ports wherethrough the fluid flows from entrance or exit ports 335, 336, 337 or 338 into or out of rotor passages 261 or 361 and thereby into or out of the cylinders 216 or 214 in rotor 315. In order to assure close sealing of the control mirrors 254- and 354, at least one of the control bodies, for example, control body 253, is borne on one end of pas sage body 355. This passage body is directly or indirectly borne in or on a respective portion or hole in housing cover 526 in such a manner that it is able to move to a limited extent along the axis relative to housing cover means 526. Force means, like spring means and/or fluid pressure means, are associated with passage body 355 in order to press passage body 355 against control body 253, control body 253 against rotor 315, rotor 315 against control body 353 and control body 253 against cover 426.

Instead of placing rotor 315 on control body 353, it would also be possible to fix rotor 355 or a shaft portion 315 in axial thrust bearings and provide an axially moveable passage body 355 on both ends of the rotor. Fluid entrance and exit passages extend through passage body 355 and their ports communicate with the respective passages or ports in a control body or directly or indirectly with passages or ports in the housing or in a cover of the machine. In operation, with the machine of FIG. 11, fluid flows from two of the entrance ports 335, 336, 337 or 338 through respective passages and through a passage body 355 and control body 253 or through a control body 353 and through rotor passages 2.61 or 361 into and out of cylinders 216 or 214 of the pump, motor or compressor.

In another embodiment of the invention, fluid contain ing chambers 360 and 361 can be provided behind the respective portions of passage body 355. They are closed directly or indirectly by respective portions or parts of the housing cover means 526. Fluid is led from an entrance or exit passage into a fluid containing chamber 360 and from the other of said passages into the other fluid containing chamber 361 through respective passage means which are not visible in FIG. 11. The fluid pressure in one or both of the fluid containing chambers 360 and 361 assists the pressing of passage body 355 against control body 253 and thereby the pressing of the already described elements against each other.

Since each control body has an entrance control port and an exit control port 262, 462, 362 or 562, and since those ports are diametrically opposed across the axis of the rotor, one diametrical section of the rotor, control bodies and passage body would have a higher loading than the other section if the one control port contains a higher pressure. This could lead to sticking or welding of the control faces.

In order to prevent such one-sided forces, the fluid containing chambers 360 and 361 are, according to a preferred embodiment of this invention, not cylindrical but are provided with cylindrical outer walls and inner walls which have axes which are eccentric relative to each other. These axes are spaced from each other within a plane which goes about through the middle of the control port.

As can be particularly seen from FIG. 12, the fluid containing chamber 360 has an outer wall face 290 which is cylindrical and the fluid containing chamber 361 has an inner wall face 291, which is also cylindrical. Both said wall faces 290 and 291 have the same axis. Both fluid containing chambers 360 and 361 are separated from each other by a medial cylindrical sealing arrangement 292, which has an axis which is eccentric to and spaced from the axis of said Wall faces 290 and 291 in the above described plane. Therefore, each of the fluid containing chambers 360 and 361 has a Wide portion and a narrow portion and these are oppositionally located one to the other.

The eifect which is obtained can, for example, be understood by comparatively examining FIGS. 12 and 14. The wider half of fluid chamber 360 is located axially of control port 262, and the narrow half of the fluid chamber 360 is located axially of control port 462. The wider half of the fluid containing chamber 361. is located axially of control port 462 and its narrow half is located axially of control port 262.

Consequently, as shown in FIG. 14, the wider half of the fluid containing chamber 360 covers the control passage 262 and the surrounding control mirror clearances, and counteracts the fluid pressures thereabout. The wide half of fluid containing chamber 361 covers the control mirror 462 and the surrounding control mirror clearances, and counteracts the fluid pressures thereabout. Similarly, the narrow half of the fluid containing chamber 360 covers the control passage 462 and the surrounding control mirror clearances, and the narrow half of the fluid containing chamber 361 covers the control passage 462 and the surrounding control mirror clearances.

When the fluid port control passage 262 is a high pressure port, then the control port 462 is a low pressure port, and vice versa. The pressure on the fluid in the control ports 262 and 462 and in the surrounding control mirror clearances tend to press the control body 253 away from rotor 315. That would result in widening of the control body clearance and in a loss of fluid and power. Since, however, the wide half of the fluid containing space is associated with a control port of higher pressure, the force of fluid pressure which is present in the respective fluid working chambers presses the passage body 355 and the control body 253 against the forces of fluid which act contrary with respect to the associated control port and its surrounding control mirror clearances with suflicient force that the forces are counteracted thereby and the control body 253 remains pressed towards the rotor 315. The control body 353 on the other rotor end is similarly pressed towards rotor 315 and the fluid forces in control passages 362 and 462 and in control mirror clearance 354 are similarly governed. In order to obtain this balancing effect and maintain the required force to press the passage body 355 towards the rotor 315, the eccentricity 297, see FIGS. 12 and 14, between the axes of wall faces 29% and 291 and the medial sealing arrange-- ment 292 must be carefully dimensioned. For calculation and defining the size of eccentricity 297, the fluid forces not only in the control ports but also in the control mirror clearances and in the closing area 662 and 563 must be taken into consideration. Otherwise the desired effect will not be obtained and the control faces might weld together or the control mirror clearances might widen. With proper dimensioning of eccentricity 297 and of the diameters of wall faces 290 and 291, the narrow half of the fluid containing chamber 360 or 361 will maintain the necessary force for pressing the low pressure port and neighboring control body clearances against the rotary control face of rotor 315; and the large half of a fluid containing chamber 360 or 361 will press the high pressure control port and the neighboring control mirror clearances against the rotary control face of rotor 315. Fluid passages or communication passages 235 and 236 may each communicate between one of the control ports 262 and 462 and of the fluid containing spaces 360 and 361.

Special attention must also be given to the closing areas 662 and 663 of the control mirrors, which temporarily close the rotor passages 261 or 361 during operation of the machine. The control clearance and the pressure in the fluid film therein varies with the rotation of the rotor. The pressure therein may be considered to be about the mean value between the pressure in the high pressure control port and the pressure in the low pressure control port. The placing and dimensioning of the fluid containing chambers 360 and 361 and the medial cylindrical sealing arrangement therebetween in accordance with this invention, as is shown in FIGS. 12 to 14, provides a radial length through each fluid containing chamber 360 and 361 of about the mean of the respective dimension through the wide and through the narrow half of the fluid containing chambers 360 and 361. This dimension is just suitable to maintain the necessary force to press the respective portions of the closing areas 662 and 663 and the neighboring portions of the control faces of control mirrors 254 and 354 together.

Thus, by the correct placement of a pair of fluid containing chambers 360 and 361, an effective and not too high force is obtained for pressing the control faces together whereby the control faces are in close operating engagement.

In accordance with this present invention, it is desirable to add radial strength to the piston actuating means or guide means by support means 43 or 341 and it is also desirable to make the inner diameters of bearings 35 or 340 as small as possible in order to reduce the frictional losses. Bearings and support rings with small diameters would permit only small piston strokes if applied to machines with heretofore utilized axial fluid supply because the inner surfaces of the support rings or bearings would touch against the outer face of a large diameter cylindrical fluid passing body and would prevent a large displacement stroke. But large displacement strokes or large piston strokes are desirable if high efliciency and power are to be realized. Therefore, the cross-sectional configuration of passage body 355 is provided with the portion of passage body located inside the support ring 341 radially upwards and downwards flattened as shown in FIG. 15. The radius of the outer faces of this portion of passage body 355 is half the diameter of the support ring 341, the axis of which, however, is located to give eccentricity 298 or 299. Support ring 341 and bearing 340 can obtain both full eccentric positions, as is shown in FIG. 15, and the full extent of a large piston stroke is therefore obtained by this important feature of the invention.

The location and configuration of the cover means and of the passage body and control bodies of this invention also make it possible to provide radial bearings very close to the rotor central portion either in the cover or in the passage body. That provides radial rotor strength and prevents deflection.

What I claim is:

1. In a radial piston machine in combination radial cylinders provided in a fluid-handling body and arranged in a plurality of axially spaced cylinder groups with pistons therein; piston shoes pivotably connected to said piston; guide means for guiding the pistons inwards and out-wards in said cylinders for intaking and expelling fluid into and out of said cylinders; passages for passing fluid into and out of said cylinders and piston shoes; central part extensions on said piston shoes and said guide means radially strengthened by the precision radial extensions located axialwards of the said fluid-handling body and partially embracing the latter, wherein each of said piston shoes is provided with a connection portion for pivotable operative connection to the associated piston; a piston shoe medial portion extending radialwards from said connection portion to the piston shoe central portion; said piston shoe central portion is provided with piston shoe axial extensions, each one in one axial direction; piston shoe peripheral extensions are provided on each of said piston shoe axial extensions; -outer guide faces are provided on portions of said extensions for being guided on portions of said guide means to move said pistons radially inwards; inner guide faces are provided on portions of said extensions for being guided on portions of said guide means to move said pistons radially outward; an elongated axial extension is provided between one of said peripheral extensions in said piston shoe central portion or its axial extension; and said elongated axial extension is extending in said one axial direction through and beyond another cylinder group of said plurality of cylinder groups.

2. The radial piston machine of claim 1, wherein said fluid-handling body is a rotor, able and borne to revolve around its axis; said cylinders are arranged in a pair of substantial radial cylinder groups each axis of each cylinder of the same cylinder group provided substantially in the same radial plane; one cylinder group axially spaced from the other cylinder group of the pair of cylinder groups; each axis of each cylinder of one cylinder group peripherally spaced from and located between axes of cylinders of the other cylinder group; radial extensions provided on each rotor portion which contains a cylinder group; said radial extensions are separated into segments by each one of said cylinders and each one axially extending slot which is provided through the respective segment of the respective of said radial extensions; each one of the peripheral and of said segment of a radial extension of the rotor forming a portion of a cylinder wall and thereby a guide face for partially guiding one of said pistons; each of said piston shoes is provided with a connection portion for pivotable operative connection to the associated piston; a piston shoe medial portion extending radialward from said connection portion to the piston shoe central portion; said piston shoe central portion is provided with piston shoe axial extensions, each one in one axial direction piston shoe peripheral extensions are provided on each of said piston shoe axial extensions; outer guide faces are provided on portions of said extensions for being guided on portions of said guide means to move said pistons radially inwards; inner guide faces are provided on portions of said extensions for being guided on portions of said guide means to move said pistons radially outwards; an elongated axial extension is provided between one of said peripheral extensions and said piston shoe central portion or its axial extension; said elongated axial extension is extending in said one axial direction, through and beyond another cylinder group of said plurality of cylinder groups; and said elongated axial extension is smaller than the width of said axially extending slots through said segments of said radial extensions of said rotor, so that said elongated axial extension of said piston shoe is able to enter at least partially into a respective slot of said axially extending slots of a respective segment of said radial extension of said rotor portion, which contains the said other cylinder group of said pair of cylinder groups.

3. The radial piston machine of claim 2 wherein said guide means consists of a revolving medial rotary ring portion provided with inner faces for guiding said outer guide faces of said piston shoes and a pair of rotary support rings which are revolving in radial bearings, which bear said revolving medial rotary ring portion and which are provided with guide faces for guiding said inner faces of said piston shoes.

4. In a fluid handling device; in combination; a housing, a fluid-handling body provided with working chambers and entrance and exit means for passing fluid into and out of said working chambers and actuator means for actuating said displacement means to periodically increase and decrease to volumes of said working chambers; at least one fluid-distributing control body provided on one axial shoulder of said fluid-handling body, one of said bodies revolving respective to the other and forming a stationary and a rotary control face between said bodies for passing fluid therethrough; a passage body located in a cover portion of said housing and being respectively thereto axialwardly movable to a limited extent; a pair of fluid-containing chambers formed between a backwards shoulder of its said passage body and each chamber of said chamber is sealed towards said cover means, passage body and to the other chamber of said pair of fluidcontaining chambers, and one of said fluid-containing chambers has a cylindrical inner wall, the other of said fluid-containing chambers has a cylindrical outer wall, the walls being centrically relatively to each other and having the same axis; a cylindrical medial sealing means associated to said chambers for sealing them from each other and said cylindrical medial sealing means is eccentrically located relatively to said walls so that the axis of said medial sealing means is distanced from the axis of said walls; a passage means communicating from said fluid-containing chambers at least indirectly to a control port in said control body for passing fluid from said control port into said fluid-containing chamber, the pressure in the fluid of said fluid-containing chamber pressing said passage body toward said fluid-handling body whereby the tight engagement between said control faces is maintained; wherein said axes of said medial sealing means and walls are distanced from each other in a plane which is normal to the axis through the smallest and biggest volumes of said working chambers.

5. The device of claim 4, wherein a center hub extends through said passage body and a portion of the housing cover extends into said center hub of said passage body and a bearing means for bearing a shaft associated to said rotor is borne in said portion.

References Cited UNITED STATES PATENTS 2,276,368 3/1942 Benedek 103-l61 3,010,405 11/1961 Tomell 103161 3,056,357 10/1962 Bohnhoff 103-161 3,078,808 2/1963 Byers 10316-1 3,213,619 10/1965 Creighton et al 103162 3,223,046 12/ 1965 Eickmann 103-161 3,304,883 2/1967 Eickrnann 103-461 FOREIGN PATENTS 822,014 10/ 1959 Great Britain.

WILLIAM L. FREEI-I, Primary Examiner 

